1. Field of the Invention
The present invention relates generally to haulage vehicles, and, more particularly, to haulage vehicles especially adapted for reducing air resistance when an empty vehicle is driven.
2. Description of the Prior Art
It is well known in the art that when a vehicle is driven, air resistance is an important factor in causing excess fuel to be consumed, even if the haulage vehicle is empty. To reduce this effect, throughout the years, a number of innovations have been developed relating to the reduction of air resistance in haulage vehicles, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 926,971, 5,782,521, and 6,685,256.
More specifically, U.S. Pat. No. 926,971 discloses a railroad car that include front air intake tubes, a front to rear air conveyor duct, and rear air output tubes. Passage of air through the front air intake tubes, the front to rear air conveyor duct, and the rear air output tubes reduces air resistance when compared to a solid front that has no air intake tubes. The volume of the front air intake tubes, the front to rear air conveyor duct, and the rear air output tubes is relatively low compared to the volume of the haulage compartment inside the railroad car. Greater reduction in air resistance could be achieved if the volume of the haulage compartment could be used for air flow, provided that the haulage compartment is empty. In this respect, it would be desirable is a haulage vehicle were provided that permitted air flow through the haulage compartment when the haulage compartment is empty.
U.S. Pat. No. 5,782,521 discloses a tractor trailer that has a retractable overhead front door and a retractable overhead rear door. When the both the front and rear doors are open, air can flow through the haulage compartment of the tractor trailer to reduce air resistance. A tractor trailer, however, must be pulled by a motorized tractor, and the presence of the motorized tractor can block the opening to the front door. In this respect, it would be desirable if a haulage vehicle were provided that includes all of a driver's cab, a motor, and a haulage compartment that are integrated into a single vehicle so that front doors of a haulage compartment are not blocked by a motorized tractor.
U.S. Pat. No. 6,685,256 discloses a trailer drag reduction system which includes an air intake opening, an air conveyor, and an outlet opening, all outside the interior of a trailer. Just as with U.S. Pat. No. 926,971, this trailer drag reduction system does not permit air to flow through the haulage compartment when the haulage compartment is empty.
Still other features would be desirable in a reduced wind resistance haulage vehicle apparatus. For example, in a conventional motorized tractor, the motor is located relatively close to the cab in which the driver sits. As a result, the driver experiences noise and vibration from the motor. In contrast, with an integrated haulage vehicle, in which the cab, the motor, and the haulage compartment are integrated, the motor can be located under the haulage compartment, at a considerable distance from the cab in which the driver sits, thereby reducing motor noise and vibration experienced by the driver.
In addition, it is well known that for a heavy load, more wheels and tires are needed to carry a heavy load in a haulage compartment than when the haulage compartment is empty. Nevertheless, a haulage vehicle comes with a fixed number of wheels and tires. Wheels and tires that roll along a road surface generate a substantial amount of kinetic resistance and require fuel consumption whether or not the haulage compartment is full or empty. However, to reduce fuel consumption for an empty haulage compartment, it would be desirable if some wheels and tires could be elevated above the road surface, so that they do not roll along the road surface when the haulage compartment is empty.
Thus, while the foregoing body of prior art indicates it to be well known to use channels in haulage vehicles for air flow to reduce air resistance, the prior art described above does not teach or suggest a reduced wind resistance haulage vehicle apparatus which has the following combination of desirable features: (1) permits air flow through the haulage compartment when the haulage compartment is empty; (2) provides a haulage vehicle that includes all of a driver's cab, a motor, and a haulage compartment that are integrated into a single vehicle; (3) provides that the motor can be located under the haulage compartment, at a considerable distance from the cab in which the driver sits, thereby reducing motor noise and vibration experienced by the driver; and (4) permits some wheels and tires to be elevated above the road surface, so that they do not roll along the road surface when the haulage compartment is empty. The foregoing desired characteristics are provided by the unique reduced wind resistance haulage vehicle apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.